Electrical plug-in connection for an automatic transmission of a motor vehicle

ABSTRACT

An electrical plug-in connection for an automatic transmission of a motor vehicle, consisting of a socket ( 6, 16 ) and a plug part engaging therein, for transmitting signals required for control of an electrohydraulic control device ( 10, 20 ) with the signals received from a signal source situated outside the transmission. The socket ( 6, 16 ) is inserted in the oil pan ( 1, 11 ) of the transmission and an electrical contact, via a connection ( 8, 18 ), automatically results when the oil pan ( 1, 11 ) and the transmission housing are assembly and an automatic electric disconnection results when they are disassembled from one another.

FIELD OF THE INVENTION

The invention relates to an electrical plug-in connection for anautomatic transmission of a motor vehicle to transmit signals requiredfor control of the hydraulic control device which signals are receivedfrom an electronic control device provided outside the transmission.

BACKGROUND OF THE INVENTION

The invention especially relates to the electrical plug-in connectionfor an electrohydraulic automatic transmission usually consisting of astarting unit such as a hydrodynamic converter, clutches and brakes, ahydraulic control device and an electronic transmission control device.The electronic transmission control device forms, from input variables,the parameters needed for the control of the automatic transmission.Input variables are signals already supplied by sensors and signals madeavailable by other control device such as the motor control device. Theelectronic transmission control device controls via output signals theelectromagnetic actuators located in the hydraulic control device.Shifts are initiated, via said electromagnetic actuators, by selectingan adequate clutch/brake combination. The pressure curve during theshift and the pressure level outside the shift are additionallycontrolled via the electromagnetic actuators.

The hydraulic control device is often mounted upon the underside of theautomatic transmission and comprises a suction snorkel, a valve housing,an intermediate plate with seal and a duct plate, the duct plate and thetransmission housing coming to abutment with each other via two faces.

Automatic transmissions for motor vehicles have an electrohydrauliccontrol generally installed horizontally or vertically and containingthe electromechanical and electronic parts which are to be connectedwith a cable harness situated outside the transmission, for example, tosupply voltage. DE 43 44 584 describes by way of example a system ofmagnetic valves, a central plug and a printer board for a hydraulictransmission control device. The electrical lines in the proximity ofthe electronic module within the transmission are laid out as massiveflat lines in the form of a pressed screen or of a flexible printedboard. The pressed screens or printed boards are then connected with asocket placed in the transmission housing after which the electricalconnection to the vehicle cable harness is created by inserting a matingplug.

Automatic transmissions are already known wherein an electronictransmission control is integrated in the transmission and situateddirectly on the hydraulic control.

In order to make possible a socket in a horizontal direction in a recessof a perpendicular wall of a transmission housing, it has already beenproposed in the Applicant's DE 199 22 819.1 to produce a pressed screen,that is, a two-dimensional arrangement and after insertion in the modulecarrier, e.g., by an extrusion coating or clamping, to connect it bysoldering, welding or riveting with the individual electrical andelectronic parts. Thereafter, the socket in a vertical position, thatis, with a downwardly directed plug opening, is connected with thepressed screen and after contact has occurred, an end of the pressedscreen is bent together with the socket by about 90° depending on theinstallation position so that the transmission socket comes to ahorizontal position. Thereafter, the socket is moved back relative toits final position to the extent that upon vertical insertion of theelectrohydraulic control, the socket does not border on the inner wallof the transmission housing. After complete mounting of the -control,the socket is located in prolongation of the installation positionbehind the port in the transmission housing.

In DE 199 03 712, an electrical plug-in connector to be used withtransmission control systems in motor vehicles has already been proposedin order to create an electrical connection between two electrical areasseparated from each other by a wall, which comprises a first plug-inconnection part that carries electrical plug-in contacts, a secondplug-in connection part that contains electric contact bushings and aguide sleeve designed for gripping through an assembly port located in awall and having the first plug-in connection part at one end and thesecond plug-connection part at the other end, means being provided forfixing to the wall. The means for connecting the guide sleeve that gripsthrough the wall with the plug-in connection part located behind it canbe designed as a kind of thread or a kind of bayonet locking system. Theelectrical connection between the inaccessible plug-in connection partwhich is, for example, the plug part provided with a pin housing, andthe electrical and/or electronic components situated upon a circuitcarrier spaced from the plug-in connection part can be implemented byflexible conductors such as sheet conductors.

In all said electrical plug-in connections known already the socket orplug parts serving as mating plugs are situated in the transmissionhousing. But in newer transmission such as have now been developed it isno longer possible to assembly one part of the electrical plug-inconnection in the transmission housing as a mechatronic solution.

The problem to be solved by this invention is to provide an electricalplug-in connection for the automatic transmission of a motor vehiclewhere a reliable, safe and automatic connection is made possible despitethe disadvantages of modern transmissions determined by installationspace.

SUMMARY OF THE INVENTION

It is therefore provided, according to the invention, that theelectrical plug-in connection consisting of a transmission socketfixedly situated to the transmission and electrically connected with theelectrohydraulic automatic control and of a plug part engaging therein,which is electrically connected with the vehicle cable harness, beconfigured in a manner such that the socket is inserted in the oil panof the transmission; when the oil pan and the transmission housing areassembled, an electrical contact occurs and when they are disassembledsaid electrical contact is disrupted. Via the vehicle cable harness theelectrohydraulic transmission control device is supplied, for example,with the vehicle voltage and/or connected with other electronic devices.

In case of an oil pan consisting of plastic material, it is of specialadvantage that the socket be fixedly connected with the oil pan byinjection molding during production.

This firm assembly of the transmission socket (or of the transmissionplug) in the oil pan eliminates a subsequent assembly of the plug-inconnection in the oil pan which would be extremely unfavorable due tosealing problems or to the narrow installation space. Thereby a tying bya cable harness is also eliminated which is extremely problematic forreasons of cost, and also the oil pan in disassembled state does notadhere to the transmission plug, as would be the case were a cableharness used.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described, by way of example, with referenceto the accompanying drawings in which:

FIG. 1 is a partial section through an automatic transmission with aninventively situated electrical socket; and

FIG. 2 is a partial section through another automatic transmissionlikewise with an inventively inserted socket.

DETAILED DESCRIPTION OF THE INVENTION

In the figures only the essential parts for understanding the inventionare shown. In the partial section through an automatic transmission fora motor vehicle shown in FIG. 1, the oil pan for the transmission whichin this embodiment conventionally consists of metal plate is designatedby 1. An electrohydraulic transmission control device is designated by10 which, in the configuration shown, has a hydraulic automatic control2, one or more actuators 3 such as pressure regulators or magneticvalves, a conventional printed board or a flexible printed board 4, anelectronic automatic control 5 and an electrical connection 8, thelatter being provided, for example, on the hydraulic automatic control5. In another design of the electrohydraulic control 10, it can also beprovided that the electronic automatic control 5 is situated in thevehicle outside the transmission.

A socket 6, according to the invention, is now provided in the oil pan 1as part of an electrical plug-in connection between the electrohydraulictransmission control device 10 or the electronic automatic control 5 anda vehicle cable harness (not shown), with an electrical contact beingindicated by 7. The fixed assembly of the socket 6 at an adequate placein the oil pan 1 makes, by way of a connection 8 of the electricconductor, an automatic contact possible during assembly of the oil panor an automatic detachment of the electrical connection when the oil panis disassembled.

In the partial section through an automatic transmission shown in FIG.2, an oil pan made of a plastic material is designated by 11, again theelectrohydraulic automatic control 20 which is a hydraulic controldevice 12, one or more actuators 13, one pressed screen or one flexibleprinted board 14 with electrical conductors 14A, one electronictransmission control device 15 and one socket 16 is inventively insertedin the oil pan 11 with an electrical connection 17. In this embodiment,the socket 16 is already advantageously inserted in the oil pan 11 byinjection molding during the production process. Again an electricalconnection, between the electrical conductor 19 extending from thesocket 16 to the hydraulic automatic control 12 and automaticallyproducing the electrical connection when the oil pan 11 is assembled onthe transmission, is designated by 18. The electrical conductor 19 canalready be integrated in the wall of the oil pan 11 during theproduction or is situated upon the inner side thereof.

The electrical connection between the electrohydraulic automatic control20 or the electronic automatic control 15 and the vehicle cable harness(not shown) is created by engagement of a plug part (not shown) of thesocket 6 or 16 inserted in the oil pan 1 or 11.

What is claimed is:
 1. An automatic transmission for a motor vehiclehaving an electrical plug-in connection for receiving transmittedsignals required for control of an electrohydraulic control device (10,20) of the automatic transmission, the transmitted signals beingreceived from signal sources situated outside the automatic transmissionand conveyed to the electrohydraulic control device (10, 20); whereinthe electrical plug-in connection comprises a socket (6, 16) with afirst portion of said socket (6, 16) electrically connectable with saidsignal sources situated outside the automatic transmission and a secondportion of said socket (6, 16) electrically connectable with theelectrohydraulic control device (10, 20), the socket (6, 16) is fixedlysecured to the automatic transmission such that when said oil pan (1,11) is assembled with the transmission housing of the automatictransmission, an automatic electrical connection occurs between thesecond portion of the socket (6, 16) and the electrohydraulic controldevice (10, 20), and when the oil pan (1, 11) is disassembled from thetransmission housing, an automatic electrical disconnection occursbetween the second portion of the socket (6, 16) and theelectrohydraulic control device (10, 20).
 2. The automatic transmissionaccording to claim 1, wherein the oil pan (11) comprises of a plasticmaterial, and said socket (16) is fixedly connected with the oil pan byinjection molding during production of the oil pan.
 3. The automatictransmission according to claim 1, wherein the electrohydraulictransmission control device comprises a hydraulic automatic control, atleast one actuator, a circuit board, an electronic automatic control andan electrical connection for engagement with the second portion of thesocket (6, 16).
 4. The automatic transmission according to claim 3,wherein the at least one actuator comprises at least one pressureregulator.
 5. The automatic transmission according to claim 3, whereinthe at least one actuator comprises at least one magnetic valve.
 6. Theautomatic transmission according to claim 3, wherein the circuit boardcomprises one of a conventional printed board and a flexible printedcircuit board.